windhoek to cape town

Has anyone done this drive, if so, how long did it take? We are trying to decide whether to fly or drive this portion of a trip. The airfare for two is about $900 so it would be quite a bit less to do a car rental. I figure it will take 15-18 hours of driving with few stops along the way but it will save around $600.

You are right, it just takes two longs days of driving but the scenery, well at least in Namibia is great.
I haven't made this trip, but travelled down south in Namibia from Windhoek. Roads are perfect and there is almost no traffic.
I guess you already figured out about drop off costs. Still cheaper though.

I have driven form the Northern end of Namibia to the Cape, and I have done Johannesburg to Windhoek (via the Fish River Canyon) and back: it was great to drive there. Beautiful scenery and roads. I would take the road and save the money for better things than a plane ride.

Thats about what I had hoped for. I did drive from KTP to Port Elizabeth a couple of years ago and enjoyed it. The Karoo was a little bleak and most of the roads were gravel and pretty much deserted, reminded me of West Texas.
The drive in Namabia should be very senic, its the northern Cape that I have my doubts about but I hope to be plesantly suprised by that area also. I have been to Cape Town several times so I am thinking that I will take an extra day or two to enjoy the scenery and take a few side trips along the way. Thanks for the comments.